Demonstrator Lorraine Reich questions how feeding the livestockMonsanto's genetically modified corn and injecting the animals with antibiotics and steroids can be good.

The activists blocked entrances to Monsanto which kept employees getting to work.

"The only way that there's going to any change in our world, it seems to me, is when it hits the pocketbook and if that's going to hurt Monsanto today today, economically, we've been effective," said Reich.